efi_loader: treat UEFI variable name as const

UEFI variable names are typically constants and hence should be defined as
const. Unfortunately some of our API functions do not define the parameters
for UEFI variable names as const. This requires unnecessary conversions.

Adjust parameters of several internal functions to tre UEFI variable names
as const.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 3e5ac38..f6d65a6 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -818,7 +818,7 @@
 			u64 *remaining_variable_storage_size,
 			u64 *maximum_variable_size);
 
-void *efi_get_var(u16 *name, const efi_guid_t *vendor, efi_uintn_t *size);
+void *efi_get_var(const u16 *name, const efi_guid_t *vendor, efi_uintn_t *size);
 
 /*
  * See section 3.1.3 in the v2.7 UEFI spec for more details on